Hold the battery vertically 2–3 in (5.1–7.6 cm) above a hard, flat surface. As alkaline batteries go bad, zinc oxide builds up inside, making the battery bouncier. This simple drop test helps you determine new batteries from old ones. Start by taking the battery and holding it above a hard, flat surface like a metal table or marble countertop.
Measure the time it takes for the battery to discharge completely. If the battery runs out of power quickly or fails to reach its rated capacity, it may need replacement. A discharge test determines the battery’s ability to sustain a steady output under load. Connect the battery to a discharge resistor and measure the voltage over time.
A healthy lithium-ion battery should read between 3.6-3.8 volts for 18650 cells. If the voltage drops quickly when discharged or spikes when charged, that’s an indication that the battery may be damaged and needs to be replaced. Another way to test a lithium-ion battery is to perform a charge cycle test. Here’s how to do it:
To test the condition of a rechargeable battery, you will need the following tools: Multimeter – A multimeter helps measure voltage, current, and resistance. Battery tester/analyzer – A dedicated battery tester can provide more accurate readings. Battery charger – A charger is required for certain testing methods.
Battery charger – A charger is required for certain testing methods. Discharge resistor – A resistor helps in conducting discharge tests. Temperature probe – This measures the temperature of the battery during testing.
For a comprehensive view of an electric car's battery health, visit a certified service centre. Trained technicians can perform diagnostic scans using specialised equipment to assess the battery's condition. Diagnostic scans can reveal in-depth information about the battery's internal resistance, capacity, and overall health.